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Multiresolution analysis of density fluctuation in supersonic mixing layer

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Science China(Technological Sciences) 2010年第2期53卷 584-591页

作者： zhao YuXin1. YI ShiHe, TIAN LiFeng, HE Lin & CHENG ZhongYu College of Aerospace and Material Engineering, National University of Defense Technology, Changsha 41.073, China 1. College of Aerospace and Material Engineering National University of Defense Technology Changsha 410073 China

Due to the difficulties in measuring supersonic density field, the multiresolution analysis of supersonic mixing layer based on experimental images is still a formidable challenge. By utilizing the recently developed nanoparticle based planar laser scattering method, the density field of a supersonic mixing layer was measured at high spatiotemporal resolution. According to the dynamic behavior of coherent structures, the multiresolution characteristics of density fluctuation signals and density field images were studied based on Taylor’s hypothesis of space-time conversion and wavelet analysis. The wavelet coefficients reflect the characteristics of density fluctuation signals at different scales, and the detailed coefficients reflect the differences of approximation at adjacent levels. The density fluctuation signals of supersonic mixing layer differ from the periodic sine signal and exhibit similarity to the fractal Koch signal. The similarity at different scales reveals the fractal characteristic of mixing layer flowfield. The two-dimensional wavelet decomposition and reconstruction of density field images extract the approximate and detailed signals at different scales, which effectively resolve the characteristic structures of the flowfield at different scales.

关键词： supersonic mixing layer density fluctuation multiresolution analysis

Primary migration and secondary alteration of the Upper Paleozoic gas reservoir in Ordos Basin,China―Application of fluid inclusion gases

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Science China Earth Sciences 2008年第S1期51卷 165-173页

作者： GONG Se 1.2 ,PENG PingAn 1.,shuai YanHua 3 ,DAI JinXing 3 &ZHANG WenZheng 4 1.Guangzhou Institute of Geochemistry,the Chinese Academy of Sciences,Guangzhou 51.640,China 2 Common Wealth Scientific and Research Organization,Petroleum Resources,PO Box 1.6,North Ryde,New South Wales,1.70,Australia 3 Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 1.0083,China 4 Research Institute of Exploration and Development,Changqing Petroleum Corporation,Xi’an 71.021.China Guangzhou Institute of Geochemistry the Chinese Academy of Sciences Guangzhou 510640 China Common Wealth Scientific and Research Organization Petroleum Resources PO Box 136 North Ryde New South Wales 1670 Australia Research Institute

The composition of fluid inclusions(FI)often represents the initial geochemical characteristics of palaeo-fluid in reservoir *** on composition and carbon isotopic composition of gas during primary migration,reservoir-forming and subsequent secondary alterations are discussed through comparing fluid inclusion gas with coal-formed gas and natural gas in present gas reservoirs in the Ordos *** results show that primary migration of gas has significant effect on the molecular but not on the carbon isotopic composition of *** and diffusion fractionation took place during the secondary migration of gas in Upper Paleozoic gas reservoir according to carbon isotopic composition of methane in *** and carbon isotopic composition of natural gas were nearly unchanged after the gas reservoir forming through comparing the FI gases with the natural gas in present gas reservoir.

关键词： secondary alteration fluid inclusion carbon isotope Ordos Basin

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基于事实和风格的多通道融合虚假新闻检测

中文信息学报 2024年第8期38卷 158-166页

作者：赵中杰郑秋生张龙中原工学院前沿信息技术研究院河南郑州450007 河南省网络舆情监测与智能分析重点实验室河南郑州450007

虚假新闻的大量传播对个人和社会都造成巨大的危害,通过智能算法检测虚假新闻是阻止虚假新闻传播的重要途径。针对不同语境中虚假新闻检测不准确的问题,该文将新闻的背景事实特征和新闻的风格特征融入到模型中,可以提高模型解决缺少背... 详细信息

虚假新闻的大量传播对个人和社会都造成巨大的危害,通过智能算法检测虚假新闻是阻止虚假新闻传播的重要途径。针对不同语境中虚假新闻检测不准确的问题,该文将新闻的背景事实特征和新闻的风格特征融入到模型中,可以提高模型解决缺少背景知识的虚假新闻检测能力,增强模型的鲁棒性,其中新闻的风格包括情感风格和文本风格。同时该文构建了多通道融合器融合新闻与背景知识的差异性特征,语义特征和风格特征,组成了基于事实和风格的虚假新闻检测框架FSFD。在CHEF中文开放数据集上的实验证明,该文提出的检测方法在F1.上比基准模型提升了2.3%,可见,该文方法适用于背景丰富的新闻,为在线社交媒体的虚假新闻检测提供有力支持。

关键词：虚假新闻检测证据检索多通道融合预训练模型

Comparison of CT-guided aspiration to key hole craniotomy in the surgical treatment of spontaneous putaminal hemorrhage: a prospective randomized study

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Frontiers of Medicine 2007年第2期1卷 142-146页

作者： zhao Jizong ZHOU Liangfu ZHOU Dingbiao WANG Renzhi WANG Mei WANG Dejiang WANG Shuo YUAN Ge KANG {1. JI Nan zhao Yuanli MD YE Xun Department of Neurosurgery Beijing Tiantan HospitalCapital University of Medical SciencesBeijing 100050China Department of Neurosurgery Hua Shan HospitalFudan UniversityShanghai 200040China Department of Neurosurgery General Hospital of People’s Liberation ArmyBeijing 100853China Department of Neurosurgery Peking Union Medical College HospitalBeijing 100730China Institute of Hygienic Economics Beijing 100050China

This study was designed to compare the approaches and efficacies of two different ways of neurosurgical management for spontaneous putaminal hemorrhage(SPH):computed tomographic-guided aspiration(CTGA)and the key-hole approach(KHA).The indications of the two approaches are also *** September 2001.to 2003,a total of 1.77 cases of SPH distributed in 1.5 hospitals all over the mainland of China were included for *** cases had three-month follow-up *** study was designed in a single-blinded manner to compare the efficacies of the different *** were 563 cases in the CTGA group,1.5 in the KHA group,and 21. cases in the conventional open craniotomy(COC)*** the CTGA and KHA groups,the mortalities at one month after operation(M1.)were 1..9% and 1..3%,respectively,while the mortalities at three months after operation(M3m)were 1..4% and 1..4%,respectively(P>0.05).The postoperative complications due to CTGA(23.7%)were not significantly different from those due to KHA(25.7%)(P=0.420).The M3m of patients with Glasgow coma scale(GCS)h8 was 3.45 and 4.0 times as much as those with GCS>8,*** M3m of patients with complications was 3.92 times as much as those without *** M3m of patients with hemorrhage volume ≥70 mL was 2.67 times as much as those50 mL.

关键词： putaminal hemorrhage surgical procedures,operative craniotomy computed tomography guided aspiration key-hole approach

RST transforms resistant image watermarking based on centroid and sector-shaped partition

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Science China(Information Sciences) 2012年第3期55卷 650-662页

作者： zhao Yao1.2*, NI RongRong1.2* & ZHU ZhenFeng1.2* 1.nstitute of Information Science, Beijing Jiaotong University, Beijing 1.0044, China 2Beijing Key Laboratory of Advanced Information Science and Network Technology, Beijing 1.0044, China 1. Institute of Information Science Beijing Jiaotong University Beijing 100044 China2. Beijing Key Laboratory of Advanced Information Science and Network Technology Beijing 100044 China

A novel digital watermarking scheme featuring centroid-based sectoring is proposed in this paper. To get higher robustness against geometric attacks, such as rotation, scaling, and translation (RST), a delicate synchronization mechanism was developed and incorporated into the proposed approach. During the process of watermark embedding, the original image was partitioned into sectors based on the image centroid. Synchronization information as well as the message bits is then embedded into these sectors. With the help of the centroid-based sectoring and synchronization information, the proposed approach is capable of restoring the correct sectoring even if it has experienced severe geometric distortion. This attribute ensures the correct recovery of embedded watermarks and contributes to the robustness of the proposed scheme. A series of experiments have been conducted to verify the feasibility and effectiveness of the proposed approach. Experimental results show that the proposed scheme possesses good robustness against RST attacks and considerable robustness against other common image processing attacks.

关键词： digital watermarking geometrical transform attacks RST transforms

基于目的语参照的汉语学习者“把”字句习得考察

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世界华文教学 2024年第1期 115-131页

作者：赵全备北京外国语大学中国语言文学学院

本文以基于用法的语言习得观和联结主义为基础,采用目的语参照的语料库对比分析方法,考察了不同水平的汉语学习者对“把”字句句法结构类型的使用情况,并比较了不同类型的“把”字句对“把”后名词、动词的选用情况。研究发现:(1.动补... 详细信息

本文以基于用法的语言习得观和联结主义为基础,采用目的语参照的语料库对比分析方法,考察了不同水平的汉语学习者对“把”字句句法结构类型的使用情况,并比较了不同类型的“把”字句对“把”后名词、动词的选用情况。研究发现:(1.动补式和动宾式是学习者最常用的“把”字句句法结构类型,状动式、动体式次之,连谓式和致使式较少使用,初级学习者对动补式的使用远多于母语者,但对动宾式使用不足。(2)与母语者相比,初中级学习者采用动宾式结构对“把”后名词、采用动补式结构对“把”后动词以及初中高级学习者采用动补式结构对“把”后名词的选用存在较大差异。(3)随着语言水平的提高,学习者对动补式、动宾式“把”字句及其名词、动词成分的选用逐渐接近母语者。

关键词： “把”字句汉语二语学习者目的语语料库

基于二层分解技术和改进极限学习机模型的PM2.5浓度预测研究

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系统工程理论与实践 2018年第5期38卷 1321-1330页

作者：罗宏远王德运刘艳玲魏帅林彦兵中国地质大学(武汉)经济管理学院武汉430074 中国地质大学(武汉)中国矿产资源战略与政策研究中心武汉430074

准确的PM2.5浓度预测对于保护公众健康和提高空气质量有重要意义,然而,由于PM2.5浓度序列的随机性、非线性以及非平稳性等特征增加了对其准确预测的难度.本文提出了一种基于二层分解技术和改进极限学习机（ELM）模型的PM2.5浓度预测方法... 详细信息

准确的PM2.5浓度预测对于保护公众健康和提高空气质量有重要意义,然而,由于PM2.5浓度序列的随机性、非线性以及非平稳性等特征增加了对其准确预测的难度.本文提出了一种基于二层分解技术和改进极限学习机（ELM）模型的PM2.5浓度预测方法,该方法融合了快速集成经验模态分解（FEEMD）和变分模态分解（VMD）两种分解技术以及经过差分演化（DE）算法优化的ELM模型.为了验证所提出预测方法的有效性,本文使用该方法对北京市和石家庄市的PM2.5浓度序列进行了预测研究.结果表明：1.相比于单层分解技术,本文提出的二层分解技术可以更加有效地降低PM2.5浓度序列的非线性及非平稳性特征;2）基于二层分解技术的DE-ELM预测模型可以显著提高PM2.5浓度的预测精度.

关键词： PM2.5浓度预测快速集成经验模态分解变分模态分解差分演化算法极限学习机

氢对体心立方Fe中位错与Cr析出相相互作用的影响

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四川大学学报（自然科学版） 2024年第3期61卷 247-254页

作者：何杰赵凯张修路西南科技大学核科学技术学院绵阳621010 江南大学机械工程学院无锡214122 江苏省食品先进制造装备技术重点实验室无锡214122 宜宾学院计算物理四川省高等学校重点实验室宜宾644000

作为第四代核反应堆结构材料的Fe-Cr基铁素体/马氏体钢,在服役环境中由于嬗变反应产生大量氢原子而导致过早失效.本文利用最近发展的Fe-Cr-H三元体系的角度依赖势函数,基于分子动力学研究了氢对体心立方Fe中刃位错与Cr析出相相互作用的... 详细信息

作为第四代核反应堆结构材料的Fe-Cr基铁素体/马氏体钢,在服役环境中由于嬗变反应产生大量氢原子而导致过早失效.本文利用最近发展的Fe-Cr-H三元体系的角度依赖势函数,基于分子动力学研究了氢对体心立方Fe中刃位错与Cr析出相相互作用的影响.结果表明,氢原子降低了位错的临界脱钉扎应力.在较低应变率(5×1.^(7)s^(-1.、2×1.^(7)s^(-1.)下,氢显著降低了临界脱钉扎应力,而在较高应变率(1.^(8)s^(-1.)下,氢引起的临界应力变化并不显著.当析出相间距较小时,氢减低临界脱钉扎应力的幅度较大,反之亦然.

关键词：氢脆位错/析出相相互作用 Cr析出相分子动力学

重度支气管肺发育不良患儿内源性呼气末正压测定及其临床结局

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中国当代儿科杂志 2024年第10期26卷 1034-1039页

作者：秦欣赵小朋张华岩广州医科大学附属妇女儿童医疗中心新生儿科广东广州510630

目的探讨重度支气管肺发育不良(severe bronchopulmonary dysplasia,sBPD)患儿内源性呼气末正压(intrinsic positive end-expiratory pressure,PEEPi)水平及不同水平PEEPi与临床结局的关系。方法回顾性分析2022年1.—2023年6月在广州市妇女儿童医疗中心住院的1.例接受过PEEPi测量的sBPD患儿的临床资料,并比较极高PEEPi(≥1. cmH_(2)O)与较低PEEPi(1. cmH_(2)O)sBPD患儿的临床表现及临床结局。结果1.例sBPD患儿在纠正胎龄31.(+3)~67^(+2)周之间进行PEEPi测量,最低为0.9 cmH_(2)O,最高为1..6 cmH_(2)O,其中50%(6/1.)患儿PEEPi≥1. cmH_(2)O。所有极高PEEPi患儿临床均存在无效触发和人机不协调现象,5例患儿无法脱离有创通气,其中4例死亡、1.气管切开带机出院。而PEEPi1. cmH_(2)O患儿仅1.死亡,其余均拔管好转出院。结论sBPD患儿可能存在高PEEPi,高PEEPi可能与sBPD患儿的不良结局有关。

关键词：支气管肺发育不良内源性呼气末正压临床结局婴儿